I've seen some traffic here to suggest that the problem was tracked 
down, but I saw nothing about it being solved completely.  Currently my 
system hangs whenever an irq trap message appears, usually after some 
sort of disk io on SATA drives. Is it fixed in the GIT patchset recently 
posted or is this still open?  

0000:00:06.0 IDE interface: nVidia Corporation CK804 IDE (rev f2) 
(prog-if 8a [Master SecP PriP])

0000:00:07.0 IDE interface: nVidia Corporation CK804 Serial ATA 
Controller (rev f3) (prog-if 85 [Master SecO PriO])
        Subsystem: ASUSTeK Computer Inc.: Unknown device 815a
        Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 225


Attached are the hdparm -I's of the drives except atapi.
If it's too big they'll be available at
http://signal-lost.homeip.net/files/sda.txt
http://signal-lost.homeip.net/files/sdb.txt
http://signal-lost.homeip.net/files/sdc.txt
http://signal-lost.homeip.net/files/sdd.txt